The presence of optical discs in entertainment and business applications is ever-increasing in today's high-tech marketplace. Optical discs offer a compact, efficient and cost-effective means of storing data and transmitting that stored data on request. Indeed, optical discs are the fastest growing form of digital data storage in the world today. Such common applications include compact discs (CD's) for music, CD ROM's for computer programs and information retrieval, such as encyclopedias and digital versatile discs (DVD's) for audio-visual entertainment as well as recording purposes.
An optical disc is comprised of a number of discrete layers. The data layer will store the data in the form of a number of microscopic pits to be read by the laser of the optical disc reader. That data layer is enclosed within a series of protective layers, top and bottom. The bottom layers, commonly referred to as the "read-side" of the disc are transparent substrates which allow the laser to pass through to read the data. Scratches to this read-side surface may affect the laser beam path, however, the manner in which data is stored on an optical disc allows for an amount of read-side imperfections without preventing the playing device from reading the disc. Nonetheless, the thickness of the read-side layer of the disc is typically in the order of 1.2 mm and this portion comprises the bulk of a conventional CD, for example.
On the top side of the disc, there is a reflective layer which is in turn protected by a discrete protective layer and a graphical layer, which normally supports the label and information pertaining to the product of the disc. The reflective layer is crucial to the successful use of an optical disc in that it reflects the data enriched laser beam to the playing device receiver where the data is read and interpreted for the user. Any breach or damage to this layer will result in the laser beam passing directly through the disc at the point of the breach or damage, thereby losing the data stored at that point. Notwithstanding the importance of maintaining the integrity of this layer, the combined thickness of the layers which comprise the top-half of a conventional CD is typically in the order of 0.3 mm (one-quarter the thickness of the read-side layers).
There is thus a need in the industry to provide additional protection of the top side of the disc, in addition to the read-side. This protection to both sides of the disc must not adversely interfere with the operation of the disc, yet it should be capable of being user-installed and should be configured so as to completely cover the disc. Reference may be had to applicant's co-pending U.S. application, Ser. No. 08/713,523 now U.S. Pat. No. 5,787,069 which describes a protective cover for an optical disc which does not adversely affect the read process of the disc. The cover completely encapsulates the disc in a snap fit protecting the disc from scratches and debris while allowing the data stored on the disc to be read by conventional optical readers.
With the protective cover, there comes a need for an easy to use apparatus for applying the cover to the disc. The apparatus should be sufficiently easy for a customer to use so that covers can be applied in a foolproof manner to discs already in the possession of the customer and also of a type which could be used by distributors which may wish to cover the disc prior to sale to the customer. Any such apparatus should ensure that the disc is completely covered in a manner which will protect the disc from scratches, debris and the like, but which will not adversely interfere with the read process of the disc.